Underreamer.



w. B. WIGLE.

UNDERREAMER.

APPLICATION FILED FEB. 6.19l7.

Patented July 23,1918.

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W. B. WIGLE..

UNDERREAMER.

APPLICATION FILED FEB. 6. |9 I 1,273,708. f Patented 23,1918.

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jfzyma'f UNITED sTATEs PATENT oEEicE. i

A WILSON B. WIGLE, OF FUI;LEERFLON,v CALIFORNIA.

UNDERREAMER..V

To all whom 'it may concern.' l j n Be itknown that I, WILSON B. WIGLE', a citizen of the Dominion of Canada, residing at Fullerton, in the county of^Orange and State of California, have invented new and useful Improvements in Underreamers, of which the following is a specification. l

The vpresent invention relates to improve- 'ments .injunderreamers such as are employed toenlar'ge well holesfto permit the lowering ofV the casing infthe hole' follow? f ing drilling. 5

The invention relates particularly to the class ofunderreamers inwhich-the cutters are collapsible so that the tool'A maybe in. serted and withdrawnv through the casing.,l For this purpose the cutters are -pivotally mounted.

It is an object of this inventionto provide, a construction whereby the pivotal construction supporting the cutters is relieved from strain whenr the tool is in use.

It is another object of this invention to provide an underrearner having a body of shell form, which is not mutilated by having cut-out portions.4 Such construction pro vides a strong durable body easily remachined. i Y Y' It is a Vfurther object to provide a construction such that the cutters are securely held against turning in the body.

I accomplish these objects by means of the embodiment of my invention illust-rated in the accompanying drawings, inwhich:

ing a casing therein and my vimproved underreamer with the cutters expanded.

Fig. y2 is a sectionsimilar to Fig. 1, showing the cutters collapsedandwithin the cas-'f Fig.l 6 is a section as seen on the'line 6e@ ofFigB.` -Y Y f Referring more particularly' to the drawings, 8 indicates a well vcasing Whichis dis-` posed within a well hole.. Within the cas# ing, as shown in Figs. 1v and 2, is my improved underreamer. T-he underreamer is comprised of a two-part stock or body con-Y sisting of a member 9 adapted to be connected to a stem anda shell 10 which con-A tains the workingparts ofthe underreamer.-

, specification qf Letters Patent.

Vhas .portions ofyarying diameter.

Patented July 23, 1918. Application mea February s, 1917. serial No.l 146,992. z 7 Members 9'andv10 arethreaded together as Ato pering portion 11 is formedatthe lowerk end j -.v of the shell,f and is adapted toV receive the.

Shanks of the cutters. 'A vcylindrical por-jVv tion 12 communicates with the portion 11j through `la portion 13 reduced yin size, and r square in cross section.V Portion'. 13 1Sf'of` t such dimensions as'to slidingly receive a .rod

which is later described. y Atthe upper'en'd'k of the shellis a portion:14oflarger'diam-l therewith.

170H Y eter than the portion12, and communicatingV f.

An annular shoulder 15 is formed between the portions 1,4 and 12..,'1'The lower faceof the shell is cut to form lugs 16, 17, 18` and V19. These lugs form 'shoul.

ders against which the cutters abutptowpre-v ventv rotation ofl the latter, and alsoto take the strain due to the .tendency of the'cutters to collapse when expanded. The upper endV 'of the shellhas a threaded stem portion 20 which engages a threaded bore inthe meinber 9, and secures the-'shelljto the member 9. A bore 21l is formed in the member 9,'and is" `in eiiect Va continuation of the portion 1li of the bore in the underreamer body. The sursoV face ofthe shell is'flattened7 as indicated atV 22a t0 'Provide wW-renchhold.

Disposed within thebore ofthe shell 'isa rod V23A which is' square in section through*- out the major portion of its length, and' cyi lindrical at the upper end. Threads'are Figure 1 is a section through` awell, showf Y providedy upon the cylindrical portion, and a nut 24 isv mountedgthereon.

Below ithe i nut and: upon the rod is a collar 25.. Sur-*I y' rounding the rod, one end abutting'the col-V y v lar and the other ,end the shoulder 26 -formed in the shell, is a springV 27. VirIhe collar 25 is of such dimensions that when .they rodv 23 Y is protracted its full amount from the shell, v

v10()v A by Vrelieving they spring "27' fromV further:`

collar 25 will rest'upon shoulder 15,' there'- strain, and eliminating any danger of breaking the spring.' The rod23'is providedwith Y a head 28 'ofT-orm. Ajthreadedfbore29'p is provided in the T-tead se aneth@ head.l maybe engaged and withdrawn for dress-7;" ing'the tool., 'or'ffor any other 'convenient4`r purpose. A transverseblore 30 inV theshell may be insertedin slot 30. This position is shown by the dotted lines in Fig'j3. The

key is then inserted, being in a position just above the nut on the rod. The head is thus kept in protracted position, so that the cutters may be removed for dressing purposes, or for changing the cutters.

. The cutters 31 and 32 are identical in construction and are provided with Shanks 33 and 34C which are arranged to conform to the bore portion 11 of the shell. Shoulders 35 and 36 are formed on the cutters between the blade portions and the Shanks. These shoulders abut the lower face of the shell and form therewith pounding surfaces taking the strain of the pounding action when the underreamer is in operation. The upper ends of the shanks are so arranged that` when the cutters are withdrawn from the shell and collapsed, they will rest against the lower face of the shell. Rounded surfaces 37 and 38are formed on the cutters and engage the well casing when the cutters are collapsed, as shown in Fig. 2. Recesses are formed in each cutter to receive the T- head 28 and each cutter is pivotally secured to the T-head by a pin, as indicated by 39 and 40.

The cutters pivot on the pins but place no stra-in thereon when the reamer is in operation. The pivot pins are also concealed under the reamer body, which keeps them in place and prevents them working out.

The cutters are provided with complementary lugs 41 and 42 which extend into the recess formed between the pair of lugs 16 and 17, when the cutters are expanded. The cutters arc also constructed with lugs similar to lugs 41-1 and Ll2 disposed diametrically opposite thereto, and which extend into the recess formed between lugs 18 and 19. Lugs 4l and 42 when disposed in their corresponding recess assist in preventing collapse of the cutters. Then a strain comes on the cutters tending to collapse them, the lugs 41 and 42 abut the lugs 1G and 17, and are prevented from moving, and thereby prevent pivoting of the critters and collapse of the same.

`When the reamer is to be inserted in the casing, the cutters are protracted from the shell to the position shown in Fig. 2. As the ends of the shanks reach the bottom of the shell, the inner faces of the cutter blades will abut one another and the cutters will be fully collapsed, the upper ends of the shanks will rest. against the bottom face of the shell, the rod 23 will have been protracted against the compression of spring 27 and collar 25 will rest upon shoulder 15. In this condition the underreamer is inserted into the casing, and the rounded portions 37 and 38 of the blades will rest against the wall of the casing', thereby holding the cutters in collapsed position. When the untendency to collapse the cutters will be re-` sisted by lugs on the cutters bearing` against those on the shell assisted by the shanks bearing against the bore of the shell. Any tendency to expand will be resisted by the shanks bearing against one another. The pounding of the underreamer is taken up by the shoulders 35 and 36 resting against the lower face of the shell so thatL no strain comes upon the pivotal support of the cutters. Any tendency ofthe cutters to turn in the shell is resisted by the lugs onthe cutters bearing against the lugs on the shell.

`What I claim is: 1. In an underreamer, the combination Lof a stock having a cavity and recesses in thev lower face; a rod slidably mounted in said 'Y stock; resilient means tending` to retract said rod; cutters pivotally mounted on said rod having shanks disposed to be seated in and lilling said cavity when said cutters are expanded, said cutters having shoulders oli"- set therefrom and disposed to engage the lower face of said shell when the cutters are expanded, and a. lug on each of said cutters at the contiguous faces thereof so disposed that a pair will be disposed in one of said recesses when the cutters'are eXpandedi to prevent further expansion, collapse and r0- tation of the same. Y

2. In an underreamer, the combination of a stock having a cavity and recesses in the lower-face; a rod slidably mounted in said shell; resilient means tending to retract said rod, said stock having means to relieve said resilient means from further strain when the rod is fully protracted; cutters pivotally mounted on said rod and the shanks disposed to be seated in and filling said cavity when said cutters are expanded, said cutters having shoulders off-set therefrom and disposed to engage the lower face of said shell when the cutters are expanded, thereby providing' pounding surfaces, and a lug on each' of the cutters at the contiguous faces thereof, so disposed that a pair will be disposed in a recess when `the cutters are expanded to prevent collapse, turning` and further expansion of the same.

In witness that I claim the foregoing I have hereunto subscribed my name this 9th day of January, 1917.

VILSON B. VIGLE.

Copies-o1 this patent may be obtained for five cents each, 'by addressing the fommissioner of Patents.

Washington, D. G. 

